Foil constructions in dry areas for infrastructure works

Genap often has the answer if work has to be carried out underground.
 
Only two projects will be mentioned here, one Dutch and one international.

Railway tunnel and the ring road at Best
The railway that cut Best in two required doubling. There were effectively two possible solutions, both of which had negative side effects.

• The high variant, whereby the track would pass through the heart of Best (at least 5 metres above normal ground level). This would leave the town permanently cut in two visually, aesthetically and functionally.
• The sunken concrete variant, whereby the track would pass under the town centre. This would be much better for the inhabitants, but this solution was so costly that it was unacceptable for the minister.

The foil variant proposed by Genap helped to bridge the enormous gap in the budget and the municipality of Best can be thankful for a rail tunnel that made an end to a great nuisance and prevented much future nuisance. (The saving by using foil was by the way some 15 million Euros. In other words, without the foil there would never have been a tunnel.)

The accesses to the tunnel are each fitted with two layers of foil. Aquatex PVC was used for the first layer that prevents the ground water from penetrating. A second layer has been laid immediately under the track to serve to hold back any pollution should any incident occur. LLDPE was used for this.
 
The follow up project to this was the ring road around Best.

Ring road Best
Two plans came together here.

1. The railway company wanted to double the rail capacity in order to remove a bottleneck. 
2. The municipality of Best wanted to construct a ring road to relieve access to Best.

This meant that a grade separation crossing had to be constructed, because where there are more than two tracks level crossings are forbidden. The conditions to be fulfilled were that:

• the track was to remain where it was, at ground level 
• the ring road was to go underneath, and there was to be no horizontal pollution

By using a foil construction a much more attractive and safer result was achieved within the same budget as for the use of concrete than would have been possible had this been used. Sloping embankments were constructed. 
 
As well as this, by extending the length of the access roads the incline was halved, thus considerably increasing visibility for driving and stopping. Genap used HDPE for the major part of the work, and MPG for the edge finishing.

The Øresund link
This is the permanent link across the sea between Denmark and Sweden. The route chosen was the point across the Sont where it is narrowest, between Copenhagen and Malmö. Because the link lies in the extension of the flight path to Copenhagen part of the route was not allowed to lie above the water level, so that a bridge-tunnel link had to be constructed. Foil was used to prevent the penetration of water in the access roads to the tunnel. There were two reasons for this:

1. a considerable saving in costs in comparison with concrete
2. greater traffic safety because of the sloping embankments and the gradual change from light to dark. This fine result would not have been achieved if a concrete casing construction had been used.

There were also two reasons for choosing Genap

1. The impressive service record that Genap has built up in this field over time 
2. The broad quality guarantee system that Genap offers: ISO 9001: 2000, VCA* and KIWA

Construction of the tunnel in the Øresund link
Genap deployed two welding teams during the construction, who together laid more than 85,000 m² of LLDPE foil.